There is a Julio Rosenstock paper comparing lantus to levemir in T2DM; results were very similar and the main difference was that one needed 50% more levemir to match the lantus dose ie if switching from lantus to levemir, may well need more units of levemir than lantus.
Lantus was always sold as a uniform 24 hour insulin, but in the Fritsche study (again T2DM ) it worked better in morning than evening, which suggests not uniform effect over 24 hours - so about 5% of Italains split lantus
The blood glucose shooting up from 8.00 pm to 10.00 pm could be due to the lantus running out of steam;
Hope it all goes OK
Best wishes